Pyrrolidine compounds



- BYRROLIDINEGOMPGUNDS DavidJ. Beaver, Richmond Heights, and PaulJ.!Stoff e],

St.-I:ouis,""Mo., ns's'ignors toMonsanto ChemicaPCompanyfstdliouis;Mogn-corporafion of Delaware No Drawing. "Application July 30, 1956Serial No. 600,687

8 Claims. '(Cl.1.260326.3)

This invention .relates to .new- .and .useful pyrrolidine compounds andto processes for making same.

In accordance with this/invention it has been found thatN-(halophenylcarbamyl) pyrrolidine compounds of the structure whereinand Y, respectively, are sulfur or-oxygen, wherein a,"b and care'hydrogen or halogen, and wherein v at least two of saidsubsti'tuents a,-b andc are halogen, are useful in the control ofnoxious vegetation lMan'y of these compounds are useful bacteriostats,particularly with respect to control of Micrococcus pyogenes var.

aureus. The new compounds are prepared by reacting pyrrolidine-Z-thioneor pyrrolidine-2 one with a halophenylisocyanate of the structure a NCXwherein X is sulfur or oxygen, and wherein a, b and c have theaforedescribed significance in an inert solvent at a temperature in therange of room temperature to the reflux temperature of the system.

The compounds of this invention which are effective in the control ofbacteria are the N-(halophenylcarbamyl) pyrrolidine-Z-thiones, and asillustrative of their preparation is the following:

Example I To a suitable reaction vessel is added and intimately mixed5.1 parts by weight of pyrrolidine-Z-thione, 9.4 parts by weight of3,4-dichlorophenylisocyanate, and 24 parts by weight of acetone. Themass is agitated for about 2 hours. Approximately 50% of the acetone isevaporated and to the residue is added 20 parts by weight of diethylether and the mass agitated for a short period and filtered. Theprecipitate is filtered otf, dried and recrystallized from an anhydrousmixture of ethyl alcohol and acetone. The fine granular white powdermelting at 17l.9-172.8 C. is N-(3,4-dichlorophenylcarbamyl)pyrrolidine-Z-thione.

Employing the procedure of Example I but replacing3,4-dichlorophenylisocyanate with an equal Weight of3,5-dichlorophenylisocyanate, there is obtained N-(3,5-dichlorophenylcarbamyl) pyrrolidine-Z-thione.

Employing the procedure of Example I but replacing United States PatentO 2,829,146 Patented Apr. 1, 1 95s 3,4-dichlorophenylisocyanate with achemically equiva- J andwdimethyl formamide. The resultantdried productis a softyellowpowdermelting at l 26.7.1-27.7 .C. and

is identified as'N .(..3,4 dichlorophenylthiocarbamyl)pyrrolidine-Z-thione. p r

Example 111 To a suitable reaction vessel is added and intimately mixed9.4 parts by weight of 3,4rdichlorophenylisocyanate, 4.3 parts by weightof pyrrolidine '2-one and 40 parts by weight 'of diethyl ether. The massis agitated for 1 hour at approximately .room temperature and the otheris evaporated. The white granular product so obtained is identified asN-(3,4-dichlorophenylcarbamyl) pyrrolidine-Z-one, melting point151.8-152.7 C.

' The :new icompounds vvhen employed in the control of noxiousvegetation Whether grasses or broadleaf plants may be used in the formof aqueous suspensions or oilin-water emulsions, but preferably aqueoussuspensions containing a phytotoxic amount of the N-(halophenylcarbamyl)pyrrolidine-Z-thione or -2-one. The aqueous suspensions may be obtainedsimply by dissolving the pyrrolidine compound in a suitable solvent anddispersing the solution in water employing a wetting agent. Dispersingor emulsifying agents such as the alkyl aryl sulfonates and thepolyethyleneglycol derivatives are advantageously employed in thepreparation of the herbicidal suspensions or emulsions and a wetting orpenetrating agent is desirable for simple aqueous suspensions. The newherbicides are preferably applied by spraying aqueous suspensions or oilemulsions of the same, this method afiording an easy and inexpensive wayof destroying noxious vegetation. For general utility aqueoussuspensions in concentrations of 0.01 to 10 parts of the new herbicideper 100 parts water may be employed.

In order to illustrate the bacteriostatic activity of theN-(halophenylcarbamyl) pyrrolidine-Z-thiones, i. e. compounds of thestructure where m is a whole number from 2 to 3, and wherein the phenylradical (-C H is free of ortho substituents,N-(3,4-dichlorophenylcarbamyl) pyrrolidine-Z- thione was incorporated inan alkali metal fatty acid soap in a Weight ratio of one part per 50parts soap. Aliquots were added to a Sabourards dextrose agar medium soas to give concentrations in parts per million as set forth 'below ofthe respective compounds in the agar. The agar in each case was thenpoured into a petri dish, allowed to harden and then inoculated wistandard culture of Micrococcus pyogenes var. aure standard resistance.The incubation in each instanc made at 37f C. for 48 hours. The extentof growth is noted below:

Compound/Concentration, p. p. m. 100 10 l1-(N-mrbox-3,4-diehloroanil1de) pyrrolldine-2- thione none none noneWhile this invention has been described with respect to certainembodiments, it is not so limited and it is to be understood thatvariations and modifications thereof obvious to those skilled in the artmay be made without departing from the spirit or scope of thisinvention.

What is claimed is:

1. Compounds of the structure wherein X and Y, respectively, are atomsselected from the group consisting of sulfur and oxygen, wherein a, band c are atoms selected from the group consisting of hydrogen andhalogen, wherein at least two of said substituents a, b and c arehalogen, and wherein the halogen substituents are selected from thegroup consisting of bromine and chlorine.

2. Compounds of the structure wherein m is a whole number from 2 to 3,and wherein wherein Y is selected from the group consisting of sulfurand oxygen, with a halophenylisocyanate of the structure NCX wherein Xis sulfur or oxygen, and wherein a, b and 0 have the aforedescribedsignificance in an inert solvent at a temperature in the range of roomtemperature to the reflux temperature of the system.

References Cited in the file of this patent UNITED STATES PATENTS2,651,639 Angler Sept. 8, 1953

1. COMPOUNDS OF THE STRUCTURE